<!DOCTYPE html>
<html>
<head>
  <style type="text/css">
    #scrollable {
      margin-top: 50px;
      margin-left: 50px;
      width: 200px;
      height: 200px;
      overflow: scroll;
    }
    #touchaction {
      touch-action: pan-y;
    }
    .content {
      width: 1000px;
      height: 900px;
    }
    #handler {
      width: 100px;
      height: 100px;
    }
  </style>
</head>

<body>
  <div id="scrollable">
    <div id="touchaction">
      <div id="handler"></div>
      <div class="content"></div>
    </div>
  </div>
  <script>
    // A blocking touch handler should prevent scrolling in that region.
    document.getElementById('handler').addEventListener('touchstart', function(e) {
      e.preventDefault();
    });
  </script>
</body>
</html>
